Pass tank for processing film and improved interlock therefor



Aug." 24, 1965 mss TANK FOR Filed May 21, 1962 L. W. GACKI ETAL PROCESSING FILM AND IMPROVED I NTERLOCK THEREFOR 4 Sheets-Sheet 1 INVENTCIJRS fiawmhlmx/ 1965 L. w. GACKI ETAL 3,202,073

D INTEHLOCK THEREFOR PASS TANK FOR PROCESSING FILM AND IMPROVE Filed May 21, 1962 4 Sheets-Sheet 2 INVENTO Rs Leo/men ($07 4494 7274 MF/ZD I Aug. 24, 1965 L. w. GACKI ETAL 3,202,073 PASS TANK FOR PROCESSING FILM AND IMPROVED INTERLOCK THEREFOR Filed May 21, 1962 4 Sheets-Sheet s Aug. 24, '1965 L. w. GACKI ETAL PASS TANK FOR PROCESSING FILM AND IMPROVED INTERLOCK THEREFOR Filed May 21, 1962 4 Sheets-Sheet 4 INVENTORS Asa/mm W M44 United States atet 3,202,073 PASS TANK FOR PROCESSING FILM AND IMPROVED INTERLOCK THEREFOR Leonard W. Gacki, White Plains, and Walter A. Winfield,

Hawthorne, N.Y., assignors to Medical Metals Incorporated, a corporation of New York Filed May 21, 1962, Ser. No. 196,358 6 Claims. (Cl. 95-90) This invention pertains to film processing and developing apparatus for photographic film. More specifically, the invention relates to a film processing system in which one tank of the system has uniquely adaptable light sealing means. Such a system is particularly adaptable to the processing of X -ray film in which processes such as developing and fixing, requiring the total exclusion of light, are carried on in a darkroom and final processing, such as washing and inspection of the negatives in process, may occur at a location remote from the darkroom under ordinary lighting, the negatives in process being transferred from one location to another, while undergoing processing, through a carefully sealed light excluding area or tunnel between the two areas. Tanks equipped with facilities of the type described are known as Pass tanks. In a busy photographic laboratory where large quantities of negatives must be processed in relatively short periods of time, processing in transit is a generally recognized procedure. The requirement of keeping the negatives in process moving from darkroom to inspection and, at the same time, insuring that no light reaches the critical surfaces of film undergoing processing during its continuous progression from darkness to light with the least possible delay, is one which, to my knowledge, has never been satisfactorily met by the pass tanks of the prior art.

Tanks having separate, light excluding closures at either end of the pass" or tunnel are quite generally known. In many such tanks, each closure element is provided with its own latch or locking means. An operator at either end of the tunnel must be depended upon for manual opening or closing of his particular door in proper sequence. Neither operator can become aware of the position of the closure at the opposite end of the tunnel without an elaborate, time consuming and uncertain signalling system. Neither operator can be sure that when he opens his door that the other door may be left inadvertently ajar or opened simultaneously, thereby damaging or ruining completely all of the negalives still undergoing critical darkroom processing.

The tank of the instant invention constitutes an important advance in the art of pass tank processing structures in that the light excluding means at either end of the pass or tunnel is automatically applicable and self locking. An additional feature of the invention inheres in the fact that the opening, closing or locking of the doors or other means utilized for excluding light, may be completely controlled by a single operator or technician at the most critical end of the pass," namely in the darkroom.

In accordance with the present invention, a pass tank, having automatically applied and locked light excluding members, may comprise a single tank or a train of separate tank units extending between a darkroom and a completely illuminated final processing or inspect-ion area in a photographic processing laboratory. Midway between the ends of the tank structure is a section having 3,202,073 Patented Aug. 24, 1965 ice with other and further objects thereof, reference i had to the following description taken in connection with the accompanying drawings while its scope will be more particularly pointed out in the appended claims.

In the drawings:

FIG. 1 is a perspective view of a multi-unit pass tank system constructed in accordance with the invention and showing the structures in a typical environment.

FIG. 2 is an enlarged perspective view illustrating structural details of the interior of the light excluding hood or cover of the tank of FIG. 1 parts of the processing structures being eliminated to emphasize the interior detail.

FIG. 3 is a plan view of the hood or cover with parts of the cover being cut away to show the paired, automatic locking elements.

FIG. 4 is a front elevational view of the pass tank hood with portions of the front structure cut away to depict the automatic locking structure with latching members in neutral position. Position of the locking structure with one door opened is shown in shadow detail.

FIG. 5 is a detailed front elevation of one of the latching or locking members in door locking position.

A pass tank system of preferred form and built in accordance with the present invention is shown in a typical, through-the-wall environment in FIG. 1. A tank or train of tank units 10 having sections 11 and 12 on opposite sides of a wall 13 separating an unrestrictedly lighted, final processing or inspection area generally designated 14 from a darkroom area 15 visible through a doorway 16 is arranged for the safe passage of film negatives in process from the darkroom to the final washing tank section 11. An intermediate tank section 30 having a cover or hood 17 is depicted as extending through carefully shaped and sealed openings through an intervening wall 13 so. as to provide a completely light tight tunnel for passage of negatives suspended in auxiliary processing tanks 28. At either end of the light excluding cover 17 are oppositely opening hinged doors or covers 18, one door opening into the area 14 and the other into the darkroom 15. Each door is equipped with a handle 19. A sliding, light excluding panel 20 may be lowered or raised to permit communication between a technician stationed in the darkroom and the operatives working in the final inspection area when such intercourse will not be detrimental to the work in process in the darkroom.

To all intents and purposes, the darkroom processing section 12 and the inspection-washing section 11 may be identical structures each having one or more compartments 21, 21a, into which temperature controlled fluid may be filled and circulated by selective operation of a panelled control system generally indicated at 23 via pipe lines 22 in a manner well understood in the art or the separate sections may be completely different tank struc tures. For example, section 11 may be an open tank suitable for washing only; section 12 may be a partitioned tank suitable for maintaining separate developing and fix ing solutions whereas section 30 may be a cascade type washing unit which may be desirable for certain systems. Each tank or compartment may be equipped with a separate drainage system as through pipelines 24, 25 via suitable drains (not shown) in compartment sides or bottoms. It will be noted that temperature and drainage pressure controls are located at the front of each tank section as is shown by the broken away portion of tank front plate 29. Handles 26 facilitate removal of panel supports or plumbing shields for service or inspection. Each tank section may be separately equipped with legs 27 which may be adjustable by means (not shown) in a manner well understood in the art to insure even distribution of the fluids within the separate auxiliary tanks or compartments.

Tanks of the type described generally are constructed of stainless steel though rubber or suitable plastic materials may be utilized without departing from the spirit of the present invention. It will be understood also that the plumbing revealed by cutting away a portion of the interchangeable front panel of the tank 11 is purely illustrative and may assume any of a wide variety of forms, such structures being well known in the art and constituting no part of the invention claimed herein.

Within the main tank compartment 21 auxiliary processing tanks of a variety of sizes and shapes may be interchangeably suspended. Developing, fixing or other processing solutions customarily are maintained in these units under controlled temperatures, the individual film negatives being transferred from one auxiliary to another, transfers being interspersed with washings in the main tank fluids. This type of processing lends itself particularly to systems requiring the use of pass tanks of the type of the present invention.

Between the darkroom processing tank section 12 and the washing-inspection section 11 of the pass tank train depicted in FIG. 1, is an intermediate tank section 30 which could be an integrally constructed unit in a single tank system but which is shown as a completely separate structure slidably positionable between the two processing sections. Mounted upon the four walls of the pass" or intermediate section 30 so as to cover that section completely and exclude all light therefrom and being extended through the wall 13 and into the darkroom is a hood or cover 17 having identical doors, hinged as at 31 and being arcuately movable by handles 19. Details of the automatic locking features contained within the hood will be described subsequently in connection with other figures of the drawings.

In FIG. 2, an X-ray technician is shown transferring a negative in process from one of the auxiliary tanks 28 through an open door of the tunnel or hood 17 for further processing or washing in the pass tank 30 previously described. The undersurfaoe of the cover or door 18 has affixed thereto a bracket 33 supporting a locking pin 34 extending outwardly so as to be brought into contact with locking assembly 35 suspended from the inner wall of the pass tank. Also shown are details of the auxiliary tank structure 28 which has a T configuration and thus is supported upon a ledge or bracket 36 on the inner wall of the main tank 11a. The operator is holding a negative 37, clipped or otherwise fastened to a rack 38 which may be supported at either end by members 39 welded or otherwise fixed within the auxiliary. When supported in the manner described it will be understood that the negatives are completely immersed in the processing fluids maintained within the auxiliaries or compartments.

The structure so far described is applicable to a wide variety of tank combinations. The intermediate tank shown in FIG. 2, for example, is a cascade unit in which excess fluid and impurities are cascaded over a barrier 50 into a drainage compartment of trough 51 from which the excess fluid is drained through a filter 52 in the scupper which connects with drainage piping 24 previously described. Cascade tanks exhibit facilities'for cleaning not found in tanks of other types and, due to the speed.

at which such units may be cleaned during processing of negatives, are particularly suitable for use in pass tank structures of the type described herein. The hood 17, of course, may be readily interchangeable with intermediate tank sections of other types provided the supports are similarly dimensioned.

Beneath the hood 17 is shown the automatic hood locking means of the invention generally designated as as sembly 35 and comprising a fixed plate 41, a tiltable element 42 having a pivot member 43 and being mounted in close adjacency to the plate. Fixed at one corner of the tiltable element is a connector 44 to which is applied a rod or other member 45 leading to a similarly constructed latching assembly 46 at the other end of the hood and partially concealed by the hood cover in this figure. Structure and functions of the automatic hood locks which constitute important elements in the present invention will be described in connection with FIGS. 3 and 4.

In FIG. 3, and, as more clearly depicted in FIGS. 3 and 5, structural and functional details of the hood interior including the unique, automatically applicable, light sealing and locking thereof, previously touched upon, are shown. Portions of the front plate and the hinged doors 18 have been broken away to reveal structural details more clearly. Atttached in any suitable manner to the side walls 60, 61, of the hood 17, as by screws or bolts 62 through bushings 63 are stationary mounting plates 64 carrying pivot lug member 65 and restraining member 69, by means of which tiltable element 70 may be moved when engaged by lock actuating pin 34, here shown afiixed to a small section of broken away portion 71 of a bracket or other support 33 fixed to the cover 18. Pivotably fixed to tiltable member 70 which may be a plate 42, is an element 72 holding plate 70 and member-44 loosely separated by lug 69 so that both plates may turn slightly upon element 72. The flanged end 73 of member 44 is perforated or otherwise rendered adaptable to securement to rod or other connector. 45 and is adjustably located with respect thereto by'locking nut sets 74, 75, threadably mounted upon the end 76 of the connector, one set being applied on either side of flange 273. The bracket 71 supporting lock actuator 34 may be welded as at 77, or fixed in any suitable manner to the underside of cover 18 as shown by dotted lines appearing at the upper right hand comer of FIG. 3.

FIG. 4 permits a clearer comprehension of the functioning of parts detailed in FIG. 3. Here a hood, generally designated 17 is suitably adaptable to mounting upon a section of the pass tank system of the invention and may include end walls 78, side walls 79, the latter being broken away to reveal in elevational aspect, locking assemblies 35, 35a on the far side of the hood interior. Light restricting door members 18, having handies 19 welded or otherwise retained thereupon are hinged as at 80 for movement from the closed position of the main figure to the open position indicated by the broken line portion of FIG. 4.

It will be observed that the actuator 34 may assume three separately functioning attitudes with respect to doglegged slot 81 at one corner of tiltable member 42; a posture at the apex of the slot when the door is closed; a posture in the lower, outwardly directed portion of the dog leg when the opposite door is opened; and a posture utterly clear of the slot when the door is opened. Location of actuator 34 exactly at the apex of the slot when both doors are firmly closed permits opening either door but not both simultaneously. The positioning of the actuator 34 with respect to the slot may be precisely controlled by adjustment of members 74, 75, thus enabling maintenance of actuators at both ends of the locking system to be maintained in the necessarily criti of the locking member hanging portion 82 ing members are suspended on to provide a double parallel linked system with greater stability and endurance.

After the developed negatives cal position with respect to slots 81, 81a in tiltable mem- 'bers 42, 42a respectively.

When either door is opened by lifting handle 19, it will be readily understood that the upward movement .forces pin 34 against the overof tiltable member 42 forcing the member to pivot outwardly but being restrained in close adjacency to its supporting plate 41 during relative movement of restraining members 69, 72, with respect to the {slot 68 in plate 42. Tilting of plate 42 also moves connector 44 and adjustable link or rod 45 in the same direction as the plate thereby causing tiltable member 42a at the opposite end of the hood also .to move to the left thereby bringing overhanging portion 82a of the plate over actuator 34a which thus is firmly held in the toe of the dog leg virtually locking door 18a against any movement while the door 18 is opened. It will be particularly noted that by means of the structure de scribed only one door may be opened at one time.

After negatives or other items have been transferred through one of the opened doors, the closing of the door forces-locking actuator 34 into its slot once more, thereby reversing the movement of all the tiltable members and their connectors as previously described from the locked position clearly exemplified in FIG. 5 to the neutral position in the heavy lined showing of FIG. 4. The reversal of movement, of course, is initiated by the downward movement of the actuator which strikes against the side ofthe slot 81 opposite to that carrying the projection 82.

By the means described it will be seen that the light excluding hood of the pass tank of my invention is completely automatic in operation. Identicallylinked lockeither side of the hood When it is desired to move developed negatives from the developing and fixing tanks in the darkroom, the technician stationed at the darkroom end of the system opens-the door in are in the manner described, which automatically locks the door-on the opposite side of the hood so that no-light from-inspection area 14 may penetrate the hood until the darkroom technician wills it. are inserted in the tunnel or hooded portion of the tank system, the darkroom technician has merely to close his door which returns actuators of both doors to neutral position thereby again permitting entry to the tunnel from either door. It should be pointed out that as long as a door at either end of the tunnel is open, the door at the opposite end cannot be moved by virtue of the latching effect of members 82, 82a. Thus, negatives undergoing critical image forming reactions in the darkroom are completely safeguarded against the damaging effects of extraneous light. Having described the apparatus of the invention and the method of using i-t; what is considered to be the subject of protection by patent is enumerated in the following claims:

What is claimedis:

' '1. Ida pass tank for processing film and having a pair of oppositely opening doors hingedly mounted upon the hoodof said tank, automatic latching means comprising, a pair of latch actuators on each of said doors; a pair of parallel linked elements mounted upon stationary plates and having angularly disposed slots therein adapted to movement by either pair of said actuators; means includ ing the movement of one pair of said actuators out of said slots and alteration of the position of the other one pair of said actuators in its respective slots for tilting said linked elements to prevent the movement of the other pair of said actuators and means including the opening of either door to move one pair of said actuators to a different position in its slots to latch the opposite door and to detach completely the opened door from its latching linkage.

2. In a pass tank for processing film and including a hood positionable in light excluding attitude with respect to said tank and having doors opening outwardly at either end thereof, the improvement comprising pairs of parallel linked members pivotably mounted upon stationary plates fixed to either side of said hood and having angularly contoured slots therein; adjustable links for maintaining the parallelism of said members; a pair of latching actuators on each door each actuator being adaptable to insertion within a respective one of said slots, one or the other of said actuator pairs being maintained in its respective slots regardless of the position of the opposite door; and means including the opening of either door to move one pair of said actuators to a different position in its slots to latch the opposite door.

3. In a pass tank for processing film and including a hood positionable in light excluding attitude with respect to said tank and having doors opening outwardly at either the improvement comprising pairs of parallel support of latching members; pairs of parallel linked members mounted so as to be pivotably .movable with respect to said plates; lockable means for adjusting the parallelism of said linked members; a pair of latching actuators bracketed to each door, each actuator being adaptable to insertion within a respective one of said slots, one or the other of said actuator pairs being maintained in its respective slots regardless of the position of the opposite door; and means including the opening of either door to move one pair of said actuators to a different position in its slots to latch the opposite door.

4. In a pass tank for processing film and including a hood positionable in light excluding attitude with respect to said tank and having doors opening outwardly at either 5. light excluding hood having doors opening outwardly members; a pair of latching actuators on each door said actuators being adaptable to insertion within respective ones of said slots, one Or the other of said actuator pairs being maintained within its slots regardless of the position of the opposite door; means including the opening of either door to move one pair of said members to latching position with respect 7 8 to the actuators within its slots and to remove the other 2,521,498 9/50 Beymer et a1 292-146 pair of actuators from its slots and to detach completely 2,919,637 1/60 Carr 9590 the opening door and its actuator from its latching 2,993,426 7/61 Weisman 9590 linkage.

References Cited by the Examiner 5 NORTON ANSI-1BR, Primary Examiner.

UNITED STATES PATENTS DELBERT B. LOWE, EMIL G. ANDERSON,

2,486,036 10/49 Lacon 292146 Examiners. 

1. IN A PASS TANK FOR PROCESSING FILM AND HAVING A PAIR OF OPPOSITELY OPENING DOORS HINGEDLY MOUNTED UPON THE HOOD OF SAID TANK, AUTOMATIC LATCHING MEANS COMPRISING A PAIR OF LATCH ACTUATORS ON EACH OF SAID DOORS; A PAIR OF PARALLEL LINKED ELEMENTS MOUNTED UPON STATIONARY PLATES AND HAVING ANGULARLY DISPOSED SLOTS THEREIN ADAPTED TO MOVEMENT BY EITHER PAIR OF SAID ACTUATORS; MEANS INCLUDING THE MOVEMENT OF ONE PAIR OF SAID ACTUATORS OUT OF SAID SLOTS AND ALTERATION OF THE POSITION OF THE OTHEIR ONE PAIR OF SAID ACTUATORS IN ITS RESPECTIVE SLOTS FOR TILTING SAID LINKED ELEMENTS TO PREVENT IN ITS SLOTS TO THE OTHER PAIR OF SAID ACTUATORS AND MEANS INCLUDING THE OPENING OF EITHER DOOR TO MOVE ONE PAIR OF SAID ACTUATORS TO A DIFFERENT POSITION IN ITS SLOTS TO LATCH THE OPPOSITE DOOR AND TO DETACH COMPLETELY THE OPENED DOOR FROM ITS LATCHING LINKAGE. 